Self-contained handheld biopsy needle

ABSTRACT

A method of operating a biopsy device includes inserting a sampling probe having a first component and a second component into a biological tissue mass, the first component having a sample chamber and a side port that opens to the sample chamber, and the second component having a side opening; generating a vacuum in the sample chamber during a first drive interval; rotating at least one of the first component and the second component of the sampling probe during a second drive interval until the side port of the first component and the side opening of the second component are in radial alignment; and rotating at least one of the first component and the second component of the sampling probe during a third drive interval to sever tissue drawn by vacuum into the sample chamber to deposit a tissue sample in the sample chamber.

PRIORITY DATA AND INCORPORATION BY REFERENCE

This application is a U.S. nation phase of International Application No.PCT/US2007/076214, filed Aug. 17, 2007 which claims priority to U.S.Provisional Application Ser. No. 60/823,038, filed Aug. 21, 2006, herebyincorporated by reference in its entirety.

TECHNICAL FIELD

This invention relates to a tissue biopsy sampling device. Morespecifically, the invention relates to mechanical features of anautomatic biopsy sampling device.

BACKGROUND

Often, it is either desirable or necessary to obtain specimens of tissuefrom humans and other animals, particularly in the diagnosis andtreatment of patients with cancerous tumors, premalignant conditions,and other diseases or disorders. For example, when it is discovered thatsuspicious conditions exist, either by means of x-ray or ultrasoundimaging in various tissues of the body, a physician typically performs abiopsy to determine if the cells at the suspected site are cancerous.

A biopsy can be done either by an open or percutaneous technique. Openbiopsy is an invasive procedure using a scalpel, whereby either aportion (incisional biopsy) or the entire mass (excisional biopsy) isremoved. Percutaneous biopsy is usually done with a needle-likeinstrument through a relatively small incision, and can be performed byfine needle aspiration (FNA) or through the taking of a core biopsysample. In FNA biopsy, individual cells or clusters of cells areobtained for cytologic examination and can be prepared such as in aPapanicolaou smear. In a core biopsy, a core or fragment of the tissueis obtained for histologic examination.

Intact tissue from the organ, lesion, or tumor is preferred by medicalpersonnel in order to arrive at a definitive diagnosis regarding thepatient's condition. In most cases only part of the tissue in questionneeds to be sampled. The portions of tissue extracted must be indicativeof the organ, lesion, or tumor as a whole. Often, multiple tissuesamples from various locations of the mass being sampled may be taken.

The percutaneous biopsy procedure can be performed utilizing varioustechniques and devices. An example is a method and a device that employsa biopsy needle for cutting tissue sample as described in British PatentPublication No. GB 2018601A. In the described biopsy device, livingtissue is sucked into a cutting region under vacuum. The vacuum iscreated in the needle by employing connecting lines to a vacuumgenerator situated outside of a hand piece that holds the cannula. Thecutting of the sample is done using a cutting mechanism that movesaxially over the cannula. After sampling, the needle is withdrawn fromthe host and the sample is flushed out from the tip of the needle. Thevacuum established in the hollow needle is regulated externally from thehand-piece.

Another biopsy mechanism is described in European Patent Publication No.EP 0890 339 A1. A biopsy needle with a cutting mechanism is integratedinto a hand piece. The needle is connected via connections lines to anexternal vacuum generator and controls. The cutting device is moveableaxially in the hollow space of the biopsy needle. A rotary movement,combined with a manual lengthwise push causes the cutting device tosample the tissue from the host. The sample is transported in the hollowchannel of the needle. A similar arrangement is also shown by U.S. Pat.No. 5,526,822. In these devices, the vacuum generation mechanisms andcontrols are costly and tend to be provided in permanent fixtures thatare separate from the disposable components. A manual biopsy device isknown from German Patent No. DE 40 41 614 C1. In this device, a partialvacuum source is provided by a piston and cylinder pump. A similarpartial vacuum-assisted biopsy device can be found in InternationalPublication No. WO 96/28097, which has a syringe plunger arrangementlocated inside a manual device to create partial vacuum.

A vacuum-assisted biopsy device is described in U.S. Patent PublicationNo. 2001/0011156 A1, provides for a compactly configured hand device, inwhose housing all drive elements necessary for propelling the needle ofthe biopsy needle arrangement are provided. However, a partial vacuumsource is provided separate from the hand device, which can be connectedvia an appropriate supply line to the needle arrangement inside the handdevice at a suitable connection location.

US Patent No. 20050203439, hereby incorporated herein by reference inits entirety, describes a biopsy device for taking tissue samples, whichincludes a housing, a removable element and a control panel. Theremovable part has a vacuum pump in the form of a syringe which isdriven by a first motor and a biopsy needle which is driven by aseparate motor under the control of a controller built into a permanenthand set. The needle and syringe are provided as a sterile package unit.

There is a need for improvements in biopsy devices that provide for highperformance with low manufacturing cost, simplicity, reliability, andease of use. Current devices are complex, either requiring many partssuch as motors and drive components or providing low performance such asweak low penetration force, small sample size, poor sample integrity,etc. There is a need for design features that permit a biopsy device tobe fully automated, yet fully disposable as well as economical,susceptible to efficient manufacture, simple, and reliable.

DISCLOSURE OF THE INVENTION

The embodiments disclosed herein relate to self-contained hand-heldbiopsy needles with various features relating to automated sampling andrecovery. Among the disclosed features are ones suited tofully-disposable single-use automatic biopsy devices, such as lightweight, low cost, and simple design.

According to an embodiment, a biopsy device is provided which has ahousing and a biopsy needle projecting from the housing. The biopsyneedle has a first member that defines a sample chamber and a secondmember that defines a sample volume within the sample chamber. A pumpgenerates a vacuum in the sample volume. A primary drive element has afirst drive interval and a second drive interval. A first transmissionis driven by the primary drive element during the first drive intervalto operate the pump and a second transmission driven by the primarydrive element during the second drive interval to position the first andsecond members of the biopsy needle to define the sample volume.

Preferably, a housing encloses the pump, the primary drive element, thefirst transmission, the second transmission, and a portion of the biopsyneedle. The first and second drive intervals are sequential. The firstdrive interval overlaps the second drive interval. The second driveinterval follows after the start of the first drive interval. The firstand second drive intervals are physical displacement intervals. Thefirst and second drive intervals have identical endpoints and the seconddrive interval begins after the beginning of the first drive interval.The device includes a motor with an output connected to the primarydrive element and a controller selectively operates the motor in forwardand reverse directions.

According to another embodiment a biopsy device is provided which has abiopsy needle with tissue-penetration and tissue-samplingconfigurations. A pump is connected to the biopsy needle to generate avacuum in the biopsy needle. A first drive element is connected tooperate the pump. A second drive element is provided to configure thebiopsy needle. The first drive element has a first displacement intervaland a second displacement interval such that during the firstdisplacement interval, the first drive element operates the pump togenerate a vacuum in the biopsy needle, and during the seconddisplacement interval, the first drive element engages the second driveelement to configure the biopsy needle into the tissue-samplingconfiguration.

Preferably, the second displacement interval follows the firstdisplacement interval. Also, preferably, the first displacement intervaloverlaps the second displacement interval. Also, preferably, the seconddisplacement interval follows after the start of the first displacementinterval. The first and second displacement intervals can have the sameendpoints and the second displacement interval preferably starts afterthe start of the first displacement interval. Preferably, a motorprovides an output connected to the first drive element and a controllerselectively operates the motor in forward and reverse directions. Also,preferably, a housing encloses the pump, the first and second driveelements, and a portion of the biopsy needle.

According to another embodiment a biopsy device is provided which has abiopsy needle selectively configurable into a sampling configuration forcreating a tissue sample and an insertion/removal configuration forinserting or extracting the biopsy needle from living tissue. A pumpconnected to the biopsy needle generates a vacuum therein. A first driveelement is provided which is connected to drive the pump. A second driveelement is also connected to configure the biopsy needle. A primarydrive member is displaced through a continuous range having a firstinterval and a second interval. During the first interval, a motiveforce is transmitted through the primary drive member to the first driveelement to cause the pump to generate a vacuum and, during the secondinterval, a motive force is transmitted to the second drive element toconfigure the biopsy needle from the insertion/removal configuration tothe sampling configuration. During the second interval, a motive forcecontinues to be transmitted to the first drive element to cause the pumpto continue generating a vacuum. Preferably, the continuous range has athird interval, following the second interval, during which the seconddrive element configures the biopsy needle from the samplingconfiguration to the insertion/withdrawal configuration. Also,preferably, the first drive element is spaced apart from the seconddrive element such that the primary drive member engages the first driveelement during the first interval and, as it moves toward the seconddrive element, engages the second drive element during the secondinterval.

According to another embodiment a biopsy device is provided which has abiopsy needle selectively configurable into a cutting configuration, forcutting a tissue sample, and an insertion configuration, for insertioninto a host. A pump is connected to the biopsy needle to generate avacuum therein. A prime mover is provided with a primary output element,which can be displaced through first and second intervals. Atransmission mechanism is connected to the primary output element. Thetransmission mechanism has at least a first transmission output toconfigure the biopsy needle and at least a second transmission output tooperate the pump. The transmission mechanism is configured to cause thepump to generate a vacuum during a first displacement of the primaryoutput element and to configure the biopsy needle from the insertionconfiguration to the cutting configuration during a second displacementof the primary output element. Preferably, the transmission mechanismincludes a first drive element and a second drive element spaced aparttherefrom. Also, preferably, the first and second drive elements drivethe first and second transmission outputs, respectively. In this case,the primary output element is arranged to drive the first drive elementduring the first displacement and to move at least one of the firstdrive element and the primary drive element toward the second driveelement until it engages and drives the second drive element andthereafter drive the second drive element during the seconddisplacement.

According to another embodiment a biopsy device is provided which has abiopsy needle that is selectively configurable into a samplingconfiguration and an insertion configuration. The device has a pumpconnected to the biopsy needle to generate a vacuum therein. A motor anda transmission mechanism is provided where the transmission mechanism isconfigured to transmit motive force from the motor to the pump during afirst interval upon activation of the motor, and, during a secondinterval, following the first interval, to transmit motive force fromthe motor to the biopsy needle to change its configuration from theinsertion configuration to the sampling configuration such that asubstantial vacuum is generated by the pump before the biopsy needle isconfigured into the sampling configuration. Preferably, the motoroperates continuously during the first and second intervals. Morepreferably, both the pump and the motor operate continuously during thefirst and second intervals. In an embodiment, the pump is operatescontinuously during the first and second intervals.

The sampling configuration can include a continuous cycle that includesreceiving a tissue sample within the biopsy needle and cutting thetissue sample from a host. The biopsy needle has fixed shaft, alongitudinal axis, and a rotating shaft movably connected to the fixedshaft to rotate around the longitudinal axis. The rotating shaft caninclude a cutting blade to cut tissue samples. The samplingconfiguration can also include a continuous sampling cycle, during thesecond interval, in which a tissue sample is cut and received within thebiopsy needle, the transmission mechanism being configured to urge therotating shaft progressively during the second interval to cut a tissuesample and cause it to be received in the biopsy needle.

According to another embodiment a biopsy device is provided which has abiopsy needle, selectively configurable into a sample accessconfiguration and an insertion configuration. The biopsy needle has asample chamber. The device also has a pump connected to the samplechamber to generate a vacuum therein and a motor with a transmissionmechanism. The transmission mechanism is connected to configure thebiopsy needle and drive the pump, upon activation of the motor in afirst direction. The transmission mechanism transmits motive force fromthe motor to the pump during a first interval and, as the motorcontinues during a second interval that follows the first interval, thetransmission mechanism transmits motive force to the biopsy needle tochange its configuration from the insertion configuration to the sampleaccess configuration such that a substantial vacuum is generated in thesample chamber before the biopsy needle is configured into the sampleaccess configuration.

Preferably, upon activation of the motor in a second direction, thetransmission mechanism transmits a motive force from the motor to thepump during a third interval following the second interval andsimultaneously change the biopsy needle configuration from the insertionconfiguration to the sample access configuration to generate pressure inthe sample chamber to eject a sample therefrom. The pump is preferablyoperated during at least part of the second interval. Preferably, thepump is operated throughout the second interval. Also, preferably, ahousing encloses the pump, the transmission mechanism, and a portion ofthe biopsy needle.

According to another embodiment a biopsy device is provided which has abiopsy needle with an elongate inner cylindrical member and an elongateouter cylindrical member, the outer cylindrical member being coaxiallyaligned with the inner cylindrical member and rotatable with respect toit. The inner cylindrical member has a port and the outer cylindricalmember has a cover portion capable of being aligned with the port tocover it for insertion of the biopsy needle. The outer cylindricalmember has a cutting edge adjacent to the cover portion such that, asthe outer cylindrical member is rotated progressively about the innercylindrical member through a specified interval, the cutting edge passesover the port and covers the port. The cutting edge and port is shapedsuch may as the outer cylindrical member rotates, a progressivelygreater fraction of the cutting edge passes over the port.

Preferably, the inner cylindrical member has a trocar affixed to adistal tip thereof. Preferably, also, the cutting edge has at least aportion that is angled relative to the perpendicular to the direction ofadvance of the cutting edge. The inner cylindrical member has a surfacewith at least one barb aligned with a port edge of the port opposite thecutting edge as the cutting edge advances toward the port edge prior tocovering the port. The inner cylindrical member can have a sharp edgepartly defining the port, the sharp edge having a portion extendingtoward the axis of the inner cylindrical member and opposite the cuttingedge as the cutting edge advances toward the port edge prior to coveringthe port.

According to another embodiment a biopsy device is provided which has ahousing that defines a chamber with a biopsy needle partially disposedin the chamber. The biopsy needle has a first member that defines asample chamber and a second member may define a sample volume with thesample chamber. The device has a pump that generates a vacuum at thesample chamber and a primary drive element positioned with the housing.The primary drive element has a first drive interval and a sequentialsecond drive interval. A first transmission driven by the primary driveelement during the first drive interval operates the pump. A secondtransmission driven by the primary drive element during the second driveinterval positions the first and second members of the biopsy needle todefine the sample volume.

According to another embodiment a biopsy device is provided which has abiopsy needle with a sample chamber that has an access opening. Thebiopsy needle has a cover member movable relative to the access openingto cover the access opening. A pump is connected to the biopsy needle togenerate a vacuum in the sample chamber. A drive element is providedthat simultaneously drives the pump and moves the cover member relativeto the access opening through a sampling cycle over which the pumpgenerates a vacuum in the sample chamber and the cover member movesrelative to the sample chamber through a delay interval in which theaccess opening remains covered by the cover member and through asampling interval, following the delay interval, in which the accessopening is uncovered. The cover member has a cutting edge which cuts asample free of a host after the access opening is uncovered.

According to another embodiment, a biopsy device includes an elongateinner cylindrical member and an elongate outer cylindrical member. Theouter cylindrical member is coaxially aligned with the inner cylindricalmember and movable with respect to it along a common axis of the innerand outer cylindrical members. The inner cylindrical member has a portand the outer cylindrical member has a cover portion capable of beingaligned with the port to cover it for insertion of the biopsy needle. Adrive mechanism drives a first transmission member connected to a vacuumpump. The first transmission member drives a second transmission memberconnected to the outer cylindrical member to displace it withoutrotating it. The outer cylindrical member has a cutting edge adjacent tothe cover portion such that, as the outer cylindrical member isdisplaced along the inner cylindrical member by the drive mechanism, thecutting edge passes over the port and covers the port. Preferably, thevacuum pump is connected to the inner cylindrical member to create avacuum in communication with the port. The inner cylindrical memberwould ordinarily have a cutting tip, such as a trocar affixed to adistal tip thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated herein and constitutepart of this specification, illustrate presently preferred exemplaryembodiments of the invention, and, together with the general descriptiongiven above and the detailed description given below, serve to explainfeatures of the invention.

FIGS. 1A to 1F illustrate a biopsy needle with an external cuttingsheath according to an embodiment.

FIGS. 2A to 2F illustrate a biopsy needle with an external cuttingsheath according to another embodiment.

FIGS. 3A to 3F illustrate a biopsy needle with an external cuttingsheath according to a yet another embodiment.

FIGS. 4A to 4F illustrate a biopsy needle with an external cuttingsheath according to another embodiment.

FIG. 5A is a section view of a biopsy needle sample chamber with atissue retention feature on an edge of the chamber.

FIG. 5B is a section view of a biopsy needle sample chamber with atissue retention feature including barbs on an insert.

FIG. 6A is a graph of pressure and a timing diagram showing theoperation of a vacuum pump and a biopsy needle.

FIGS. 6B to 6E are illustrations of a sequence of operation of asampling needle.

FIGS. 7A to 7C are illustrations of the operation of a biopsy needle anddrive mechanism in successive stages of an operating cycle.

FIGS. 8A to 8C are illustrations of the operation of a biopsy needle anddrive mechanism in successive stages of an operating cycle according toa further embodiment.

FIGS. 9A to 9F illustrate, respectively, a preferred embodiment of abiopsy needle and drive mechanism in several stages of an operatingcycle.

FIG. 9G shows alternative drives that may be used to a rack in variousembodiments.

FIG. 10A illustrates another embodiment of a biopsy needle and drivemechanism employing a cam mechanism.

FIG. 10B is a planar development of a variation on the cam drivemechanism of FIG. 8A.

FIGS. 11A to 11C show a stylet and axial cutting sheath which may beused in embodiments of the invention.

FIGS. 12A to 12F show a biopsy needle embodiment for illustratingfeatures including a linear actuator, an axial cutting sheath, and aspring-activated cutting action.

MODES FOR CARRYING OUT THE INVENTION

FIGS. 1A to 1F illustrate a biopsy needle 100 with an outer sheath 105.Referring to FIG. 1A, the outer sheath 105, in the present embodiment,is cylindrical and has an opening 150 with at least one sharp edgedefining a blade 120. A cylinder-shaped inner sheath 136 has a port 130,which, in FIG. 1A, is aligned with the opening 150. The port 130provides access to a sample chamber 125 which is defined by a samplevolume within the inner sheath 136. A trocar 112 is affixed to a distalend of the inner sheath 136. A handle (not shown) is presumed to beprovided, opposite the trocar 112, to support the biopsy needle 100.

FIGS. 1B through 1F show, in section A-A, the needle 100 of FIG. 1A insuccessive stages of a sampling operation. These stages occur after theneedle 100 is inserted into living tissue, a sample of which is to beexcised for a biopsy. In FIG. 1B, the outer sheath 105 begins in aposition in which it covers the port 130. The needle 100 is insertedwhile the outer sheath 105 is in this position relative to the innersheath 136. Once the biopsy needle 100 is in position for sampling, theouter sheath 105 is rotated progressively in a counter-clockwisedirection. The counter-clockwise rotation of the outer sheath 105proceeds progressively through the stages indicated by FIGS. 10 through1F. The outer sheath 105 may be driven by any suitable drive mechanismincluding pneumatic, electrical, magnetic, hydraulic, etc. Embodimentsof suitable drive mechanisms are discussed below.

While the biopsy needle is in the insertion position shown in FIG. 1B,and after insertion into the tissue to be sampled (not shown), a vacuumis generated in the sample chamber 125 by withdrawing air from the innersheath 136. The vacuum may be generated by any suitable device.Embodiments of suitable vacuum mechanisms are discussed below. Once avacuum has been generated, the outer sheath 105 begins to rotate in thecounter-clockwise direction. In FIG. 10, the opening 150 is shown afterhaving moved partly toward a position of coincidence with the port 130.As the rotation proceeds, the blade 120 advances toward the port 130. Inthis position, the vacuum, created in the sample chamber 125, drawstissue to be sampled through the opening 150 and port 130 until itbegins to enter the sample chamber 125. The outer sheath 105, at thispoint, moves counter-clockwise toward the position shown in FIG. 1Dwhere the port 130 is fully uncovered, the opening 150 having moved intocoincidence with the opening 130. The vacuum causes tissue to be drawninto the sample chamber 125 and the outer sheath 105 continues rotatingin the counter-clockwise direction to the position shown in FIG. 1E.

As the outer sheath 105 rotates toward the position shown in FIG. 1E,the blade 120 partly slices the tissue that has been drawn into thesample chamber 125. As the blade 120 continues toward the position ofFIG. 1F, the tissue sample is completely severed from the host and heldwithin the sample chamber 125 while a portion of the outer sheath 105,behind the blade 120, covers the port 130. The biopsy needle 100 canthen be withdrawn from the inserted position as it retains the sample.Note that the present cutting mechanism, as well as others disclosed inthe present application, may be replaced by suitable alternative cuttingdevices such as levered or rotating knives with blades of varying shape,radio-frequency (RF) cutting tools, laser cutters, or any other suitablecutting device.

To remove the tissue sample, the operation depicted in FIGS. 1B through1F may be repeated. However, in this case, a positive pressure may begenerated in sample chamber 125 before starting the cycle. As the outersheath 105 rotates clockwise through the successive positions startingwith the one shown in FIG. 1F, a pressure is applied to the samplechamber 125 and the port 130 is uncovered. This causes the pressure insample chamber 125 to force the tissue sample out through the uncoveredport (about the position shown in FIG. 1D). The cycle may then continueto the point shown in FIG. 1B. Note that other sample-removal mechanismsmay also be employed, such as a mechanical member pushing the samplefrom the sample chamber 125, a fluid wash. Alternatively, a samplechamber liner, such as of thermoformed polymer, may be preinstalled andremoved by hand.

Note that the outer sheath 105 could rotate in either direction, or bothdirections, in alternative embodiments. For example, the port 130 couldbe uncovered by rotating in one direction and the cutting operation andcovering could occur after reversing the direction of rotationimmediately after uncovering the port 130. This alternative may beprovided for all of the embodiments described herein. In addition, theblade 120 may be on either or both sides of the opening 150.

The speed of rotation of the outer sheath 105 may be constant orvariable. For example, to reduce or amplify torque from the drivemechanism, a reduced force/torque transmission ratio of the drive may beprovided to level the prime mover load through the cutting phase.

Referring again to FIG. 1A, an alternative shape for the port 130 isindicated in FIG. 1A at 104. This alternative port 104 may also be usedto help reduce the instantaneous torque load on the outer sheath 105drive mechanism (not shown). The shape of the port 130, as may beconfirmed by inspection, is such that the blade 120 advances throughonly a fraction of the longitudinal extent of the sample at a giveninstant of time.

The embodiment of FIGS. 2A through 2F is similar to the embodiment ofFIGS. 1A through 1F except that an angled blade 121 is provided to levelthe cutting load. FIGS. 2A to 2F illustrate a biopsy needle 101 with anouter sheath 106. Referring to FIG. 2A, the outer sheath 106, in thepresent embodiment, is cylindrical and has an opening 151 with at leastone sharp edge defining an angled blade 121. A cylinder-shaped innersheath 136 has a port 131, which, in FIG. 2A, is aligned with theopening 151. The port 131 provides access to a sample chamber 126 whichis defined by a volume within the inner sheath 136. As in the previousembodiment, a trocar 112 is affixed to a distal end of the inner sheath136 and a handle (not shown) is presumed to be affixed, opposite thetrocar 112, to support the biopsy needle 101. Again, it should be clearthat other cutting mechanisms may be employed and the mechanical detailsof the disclosed embodiments can be modified while still providing thefunctionality disclosed.

As mentioned, the embodiment of FIGS. 2A through 2F is similar instructure and operation to the embodiment of FIGS. 1A through 1F with acutting blade 121 that forms a non-zero angle with the longitudinal axisof the outer sheath 106. This angled shape may help reduce theinstantaneous torque load on the outer sheath 105 drive mechanism (notshown). The shape of the port 131, as may be confirmed by inspection, issuch that the blade 121 advances through only a fraction of thelongitudinal extent of the sample at a given instant of time. Becausethe blade 121 is angled, it defines a helical contour with the outersheath 106. In alternative embodiments, the blade 121 could have acurved or multiple-angle configuration to achieve the same function ofreducing the instantaneous force required to perform cutting.

FIGS. 2B through 2F show, in section B-B, the needle 100 of FIG. 2A insuccessive stages of a sampling operation. These stages occur after theneedle 101 is inserted into living tissue to sample the tissue of ahost. In FIG. 2B, the outer sheath 106 begins in a position in which itcovers the port 130. The needle 100 is inserted while the outer sheath106 is in this position relative to the inner sheath 136. Once thebiopsy needle 101 is in position for sampling, the outer sheath 106 isrotated progressively in a counter-clockwise direction. Thecounter-clockwise rotation of the outer sheath 106 proceedsprogressively through the stages indicated by FIGS. 2C through 2F. Theouter sheath 106 may be driven by any suitable drive mechanism.Embodiments of suitable drive mechanisms are discussed below.

While the biopsy needle is in the insertion position shown in FIG. 2B,and after insertion into the tissue to be sampled (not shown), a vacuumis generated in the sample chamber 126 by drawing air through the innersheath 136. The vacuum may be generated by any suitable device.Embodiments of suitable vacuum mechanisms are discussed below. Once avacuum has been generated, the outer sheath 106 begins to rotate in thecounter-clockwise direction. In FIG. 2C, the opening 151 is shown afterhaving moved partly toward a position of coincidence with the port 131.As the rotation proceeds, the blade 121 advances toward the port 131. Inthis position, the vacuum, created in the sample chamber 126, drawstissue to be sampled through the opening 151 and port 131 until itbegins to enter the sample chamber 126. The outer sheath 106, at thispoint, moves counter-clockwise toward the position shown in FIG. 2Dwhere the port 131 is fully uncovered, the opening 151 having moved intocoincidence with the opening 131. The vacuum causes tissue to be drawninto the sample chamber 126 and the outer sheath 106 continues rotatingin the counter-clockwise direction to the position shown in FIG. 2E.

As the outer sheath 106 rotates toward the position shown in FIG. 2E,the blade 121 partly slices the tissue that has been drawn into thesample chamber 126. As the blade 121 continues toward the position ofFIG. 2F, the tissue sample is completely severed from the host and heldwithin the sample chamber 126 while a portion of the outer sheath 106behind the blade 121 covers the port 131. The biopsy needle 101 can thenbe withdrawn from the inserted position as it retains the sample.

To remove the tissue sample, the operation depicted in FIGS. 2B through2F may be repeated. However, in this case, a positive pressure may begenerated in sample chamber 126 before starting the cycle. As the outersheath 106 rotates clockwise through the successive positions startingwith the one shown in FIG. 2F, a pressure is applied to the samplechamber 126 and the port 131 is uncovered. This causes the pressure insample chamber 126 to force the tissue sample out through the uncoveredport (about the position shown in FIG. 2D). The cycle may then continueto the point shown in FIG. 2B.

Note that the outer sheath 106 could rotate in either direction with anappropriate repositioning of the blade 121. In addition, the blade 121may be on both sides of the opening 151. As in the prior embodiment, thespeed of rotation of the outer sheath 106 may be constant or variable toamplify torque from the drive mechanism. Referring again to FIG. 2A, thealternative shape for the port 131 indicated in FIG. 2A at 104 issubstantially as discussed with reference to FIG. 1A. However, thisalternative port 104 may provide even lower instantaneous torque loadfor a given angle because the angle of the cutting blade 121 causes thecutting front to be even smaller for a given angle of the port 131.

The movement of the outer sheath 105 or 106 of the foregoing embodimentsmay be permitted by providing that the inner sheath 135 or 136 bejournaled within the outer sheath 105 or 106. A lubricant may or may notbe provided.

Referring back to FIGS. 1A and 1B, the opening 150 may be made narrowenough, in a circumferential direction, such that the port 130 is barelyuncovered before severing of a tissue sample begins. However, it may bedesirable to provide a wider opening 150 to provide more time for tissueto be drawn into the sample chamber 125. There is a tradeoff againststructural strength in making the opening 150 wider. However, inalternative embodiments, the opening 150 may be made wider in acircumferential direction and in the extreme, only enough of the outersheath 105 may remain to barely cover the port 130. Such an embodimentis shown in FIGS. 3A to 3F and described immediately below.

FIGS. 3A to 3F illustrate a biopsy needle 200 with an outer sheath 205.Referring to FIG. 3A, the outer sheath 205, in the present embodiment,is cylindrical and has an opening 250 with at least one sharp edgedefining a blade 220. A cylinder-shaped inner sheath 236 has a port 230,which, in FIG. 3A, is aligned with the opening 250. The port 230provides access to a sample chamber 225 which is defined by a volumewithin the inner sheath 236. A trocar 212 is affixed to a distal end ofthe inner sheath 236. A handle (not shown) is presumed to be provided,opposite the trocar 212, to support the biopsy needle 201.

FIGS. 3B through 3F show, in section C-C, the needle 200 of FIG. 3A insuccessive stages of a sampling operation. These stages occur after theneedle 200 is inserted into living tissue, a sample of which is to beexcised for a biopsy. In FIG. 3B, the outer sheath 205 begins in aposition in which it covers the port 230. The needle 200 is insertedwhile the outer sheath 205 is in this position relative to the innersheath 236. Once the biopsy needle 200 is in position for sampling, theouter sheath 205 is rotated progressively in a counter-clockwisedirection. The counter-clockwise rotation of the outer sheath 205proceeds progressively through the stages indicated by FIGS. 3C through3F. The outer sheath 205 may be driven by any suitable drive mechanism.Embodiments of suitable drive mechanisms are discussed below.

While the biopsy needle is in the insertion position shown in FIG. 3B,and after insertion into the tissue to be sampled (not shown), a vacuumis generated in the sample chamber 225 by drawing air through the innersheath 236. The vacuum may be generated by any suitable device.Embodiments of suitable vacuum mechanisms are discussed below. Once avacuum has been generated, the outer sheath 205 begins to rotate in thecounter-clockwise direction. In FIG. 3C, the opening 250 is shown afterhaving moved partly toward a position of coincidence with the port 230.As the rotation proceeds, the blade 220 advances toward the port 230. Inthis position, the vacuum, created in the sample chamber 225, drawstissue to be sampled through the opening 250 and port 230 until itbegins to enter the sample chamber 225. The outer sheath 205, at thispoint, moves counter-clockwise toward the position shown in FIG. 3Dwhere the port 230 is fully uncovered, the opening 250 having moved intocoincidence with the opening 230. The vacuum causes tissue to be drawninto the sample chamber 225 and the outer sheath 205 continues rotatingin the counter-clockwise direction to the position shown in FIG. 3E.

As the outer sheath 205 rotates toward the position shown in FIG. 3E,the blade 220 partly slices the tissue that has been drawn into thesample chamber 225. As the blade 220 continues toward the position ofFIG. 3F, the tissue sample is completely severed from the host and heldwithin the sample chamber 225 while a portion of the outer sheath 205behind the blade 220 covers the port 230. The biopsy needle 200 can thenbe withdrawn from the inserted position as it retains the sample.

To remove the tissue sample, the operation depicted in FIGS. 3B through3F may be repeated. However, in this case, a positive pressure may begenerated in sample chamber 225 before starting the cycle. As the outersheath 205 rotates clockwise through the successive positions startingwith the one shown in FIG. 3F, a pressure is applied to the samplechamber 225 and the port 230 is uncovered. This causes the pressure insample chamber 225 to force the tissue sample out through the uncoveredport (about the position shown in FIG. 3D). The cycle may then continueto the point shown in FIG. 3B.

As in the previous embodiments, the outer sheath 205 could rotate ineither direction, or both directions, in alternative embodiments. Forexample, the port 130 could be uncovered by rotating in one directionand the cutting operation and covering could occur after reversing thedirection of rotation immediately after uncovering the port 130. Thisalternative may be provided for all of the embodiments described herein.In addition, the blade 220 may be on either or both sides of the opening250. As in the previous embodiments, the speed of rotation of the outersheath 205 may be constant or variable. For example, to reduce amplifytorque from the drive mechanism, a reduced force/torque transmissionratio of the drive may be provided to level the prime mover load throughthe cutting phase. As in the prior embodiments, the port 130 may haveangled edges (as has port 104 in the embodiment of FIG. 1A) to helpreduce the instantaneous torque load on the outer sheath 205 drivemechanism (not shown).

The embodiment of FIGS. 4A through 4F is similar to the embodiment ofFIGS. 3A through 3F except that an angled blade 221 is provided to levelthe cutting load, as described with reference to the embodiment of FIGS.2A through 2F.

FIGS. 4A to 4F illustrate a biopsy needle 201 with an outer sheath 206.Referring to FIG. 4A, the outer sheath 206, in the present embodiment,is cylindrical and has an opening 251 with at least one sharp edgedefining a blade 221. A cylinder-shaped inner sheath 236 has a port 231,which, in FIG. 4A, is aligned with the opening 251. The port 231provides access to a sample chamber 226 which is defined by a volumewithin the inner sheath 236. A trocar 212 is affixed to a distal end ofthe inner sheath 236. A handle (not shown) is presumed to be provided,opposite the trocar 212, to support the biopsy needle 200.

FIGS. 4B through 4F show, in section D-D, the needle 201 of FIG. 4A insuccessive stages of a sampling operation. These stages occur after theneedle 201 is inserted into living tissue, a sample of which is to beexcised for a biopsy. In FIG. 4B, the outer sheath 206 begins in aposition in which it covers the port 231. The needle 201 is insertedwhile the outer sheath 206 is in this position relative to the innersheath 236. Once the biopsy needle 201 is in position for sampling, theouter sheath 206 is rotated progressively in a counter-clockwisedirection. The counter-clockwise rotation of the outer sheath 206proceeds progressively through the stages indicated by FIGS. 4C through4F. The outer sheath 206 may be driven by any suitable drive mechanism.Embodiments of suitable drive mechanisms are discussed below.

While the biopsy needle is in the insertion position shown in FIG. 4B,and after insertion into the tissue to be sampled (not shown), a vacuumis generated in the sample chamber 226 by drawing air through the innersheath 236. The vacuum may be generated by any suitable device.Embodiments of suitable vacuum mechanisms are discussed below. Once avacuum has been generated, the outer sheath 206 begins to rotate in thecounter-clockwise direction. In FIG. 4C, the opening 251 is shown afterhaving moved partly toward a position of coincidence with the port 231.As the rotation proceeds, the blade 221 advances toward the port 231. Inthis position, the vacuum, created in the sample chamber 226, drawstissue to be sampled through the opening 251 and port 231 until itbegins to enter the sample chamber 226. The outer sheath 206, at thispoint, moves counter-clockwise toward the position shown in FIG. 4Dwhere the port 231 is fully uncovered, the opening 251 having moved intocoincidence with the opening 231. The vacuum causes tissue to be drawninto the sample chamber 226 and the outer sheath 206 continues rotatingin the counter-clockwise direction to the position shown in FIG. 4E.

As the outer sheath 206 rotates toward the position shown in FIG. 4E,the blade 221 partly slices the tissue that has been drawn into thesample chamber 226. As the blade 221 continues toward the position ofFIG. 4F, the tissue sample is completely severed from the host and heldwithin the sample chamber 226 while a portion of the outer sheath 206behind the blade 221 covers the port 231. The biopsy needle 201 can thenbe withdrawn from the inserted position as it retains the sample.

To remove the tissue sample, the operation depicted in FIGS. 4B through4F may be repeated. However, in this case, a positive pressure may begenerated in sample chamber 226 before starting the cycle. As the outersheath 206 rotates clockwise through the successive positions startingwith the one shown in FIG. 4F, a pressure is applied to the samplechamber 226 and the port 231 is uncovered. This causes the pressure insample chamber 226 to force the tissue sample out through the uncoveredport (about the position shown in FIG. 4D). The cycle may then continueto the point shown in FIG. 4B.

As in the previous embodiments, the outer sheath 206 could rotate ineither direction, or both directions, in alternative embodiments. Forexample, the port 231 could be uncovered by rotating in one directionand the cutting operation and covering could occur after reversing thedirection of rotation immediately after uncovering the port 231. Thisalternative may be provided for all of the embodiments described herein.In addition, the blade 221 may be on either or both sides of the opening251. As in the previous embodiments, the speed of rotation of the outersheath 206 may be constant or variable. For example, to reduce amplifytorque from the drive mechanism, a reduced force/torque transmissionratio of the drive may be provided to level the prime mover load throughthe cutting phase. As in the prior embodiments, the port 231 may beangled (as is 104 relative to 130 in FIG. 1A) to help reduce theinstantaneous torque load on the outer sheath 206 drive mechanism (notshown).

FIG. 5A is a section view of a biopsy needle 300 sample chamber 315 witha sharpened, curved, or jagged edge of a chamber opening 309. The edge302 helps to keep a tissue sample drawn into the sample chamber 315 by avacuum, from retreating during the cutting operation. The configurationof the biopsy needle 300 may be similar to the configurations of any ofthe foregoing embodiments but the configuration shown is similar to thatof FIGS. 3A to 3F. As an outer sheath 306 rotates around an inner sheath304, the cutting blade 310 advances across the opening 309 while theedge 302 helps to ensure the tissue does not retreat. Because thecutting blade 310 is on the outside sheath 306, an inwardly-directededge treatment, represented as edge 302, may be provided withoutinterfering with the operation of the cutting blade 310 or outer sheath306.

The embodiment of FIG. 5B is similar to that of FIG. 5A except that thebiopsy needle 301 configuration is closest to that of FIGS. 1A to 1F,although any of the foregoing configurations may be employed. Instead ofan edge 302 as in the embodiment of FIG. 5A, the embodiment of FIG. 5Bhas an insert 328 which fits inside the sample chamber 316. The inserthas a portion 321 with a barbed surface 320 that is opposite the cuttingblade 332. As in the previous embodiment, as an outer sheath 330 rotatesaround an inner sheath 334, the cutting blade 332 advances across theopening 329 while the barbed surface 320 helps to ensure the tissue doesnot retreat. Because the cutting blade 332 is on the outer sheath 330,inwardly-directed barbs may be provided without interfering with theoperation of the cutting blade 332 or outer sheath 330.

In the foregoing embodiments, it is preferable for a substantial vacuumto be generated before the biopsy needle is actuated for cutting. Thisis so that a poor sample specimen does not result due to the cuttingoperation getting underway before the tissue sample is drawn well intothe sample chamber. This can be ensured in a variety of ways, forexample by providing a drive system with independently controlled vacuumsource and biopsy needle that are sequenced to generate the vacuumbefore the biopsy needle is placed into a configuration for sampling.FIG. 6A illustrates various sequencing operations and will be used todiscuss the sequencing and variations of it.

Referring now to FIG. 6A, a self-contained device such as describedhereinbelow or, for example, in US Patent Application No. 20050203439,incorporated by reference above, or any other vacuum source, may take afinite period of time to generate a terminal negative pressure. Forexample, a displacement pump that increases a contained volume, at alinear rate, produces a vacuum—assuming there are no leaks—characterizedby an exponential pressure curve as indicated at 408. Similarly, such apump operated in reverse generates a pressure according to an incliningexponential positive pressure curve as indicated at 410.

The vacuum is preferably established when the sample chamber isuncovered. This may ensure that the severing operation can be completedand the sample secured without the sample chamber being open for a longinterval. In principle this is not essential, but in practice it may bedesirable for various reasons: (1) an imperfect fluid seal may exist sothat a progressive vacuum may not reach a desired peak level; (2) excessfluid may be drawn from the host, thereby compromising the vacuum andproducing an undesirable result when a solid specimen is required; and(3) excessive fluid may be accumulated in the tissue sample due to anextended exposure to the vacuum, while attached to the host. Othereffects such as compliance in the biopsy device's fluid circuit andother factors may also favor an operating sequence in which the host isexposed to the vacuum as briefly as possible. In all of the disclosedembodiments, means of anchoring tissue samples other than vacuum may beemployed. For example, external pressure on the host tissue from outsidethe patient body (e.g. by means of a tissue compression device or manualpressure by the practitioner) may be employed alone, or in addition tovacuum, for forcing samples into the sample chamber.

The time during which a vacuum pump is operated to create the pressurecurve, shown at 408, is indicated by the bar 402. For the entire periodt0 to t5, a vacuum pump may be operated. At a point after a substantialvacuum is generated, for example t2, the sample opening (e.g., as port130 in FIG. 1A) may be opened 422. After the sample chamber is opened424, the tissue sample, having been drawn in, will be cut 420 at a latertime t₃ and the opening subsequently closed 424 during interval t₄ tot₅. In this way the opening and cutting operations are performed towardthe end of the vacuum generation cycle 402 which takes place over theinterval from t₀ to t₅, although it may be paused earlier, depending onthe various factors mentioned.

The above sequencing may be achieved by employing independent drivemechanisms for the vacuum and biopsy needle. In a design suitable for adisposable biopsy needle it may be preferred to have a single drivesystem that can achieve the same operation sequence as just described ina manner that is reliable, with a simple a structure and low cost, byemploying a single mechanical drive, as discussed below.

An embodiment of a biopsy needle 448, similar to the embodiment of FIGS.1A and 1B, is illustrated by FIGS. 6B through 6E. In this embodiment,the outer sheath 105 (FIG. 1A) corresponds to the outer sheath 450,which has an opening 452. The inner sheath 130 (FIG. 1A) corresponds tothe inner sheath 456 which has an opening 454. Either of the outersheath 450 or the inner sheath 456 can have a cutting edge (for exampleat 451 on outer sheath 450) to cut a tissue sample, as discussed above,which is drawn into a sample chamber 458 by a vacuum generated therein.The present embodiment operates in a manner that is similar to what isdescribed with reference to FIGS. 1B through 1F, except that the totalangular displacement of the outer sheath 450 is greater in the presentembodiment, to generate a delay from the onset of the operation of thevacuum generating device and the opening of the sampling device, as willbe explained, presently.

In the series of figures, FIGS. 6B through 6E, a positive-displacementpump is shown at 480. In the series of figures, the outer sheath 450 isprogressively rotated counter-clockwise as a piston 472 of the pump 480is progressively displaced from the initial position indicated at 485,to create a vacuum in a line 474 connected to the sample chamber 458. Asthe outer sheath 450 is rotated from the insertion position shown inFIG. 6B to the position shown in FIG. 6C, the piston 472 is displaced,progressively as shown to draw a negative pressure in the line 474. Asthe outer sheath 450 is rotated further through the positions of FIGS.6D and 6E, the piston 472 is displaced further until the sample chamber458 is exposed and a sample is drawn into the sample chamber 458 andseparated from the host. The final state is indicated at FIG. 6B withthe pump 480 in the position indicated at 486, rather than the initialposition indicated at FIG. 485.

It will be observed that the above operation of the needle 448 and pump480 is effective to provide the sequencing of the vacuum creation andsampling cycle described above with reference to FIG. 6A. That is, thesample chamber 458 remains closed as the pump 480 is continuouslyoperated to create a vacuum until the sample chamber 458 is opened atthe final phase of vacuum generation. Referring particularly to FIG. 6B,it will also be observed that the outer sheath and the vacuum source areboth operated continuously during the entire cycle so that a singledrive 481 can move both the outer sheath 450 and the pump piston 472continuously without any additional provisions for sequencing because adelay can be incorporated in the arrangement and configuration of theinner 456 and outer 450 sheaths. Referring particularly to FIG. 6C, asingle drive 483 may also drive the pump 480 which in turn may drive theouter sheath 450 through a drive element 485 or the drive element 485may be a single drive element that drives both the pump 480 and theouter sheath 450. Thus, a transmission configured to apply motive force,simultaneously, to rotate the sheath and to drive the vacuum source,will provide the desired operational sequence.

Referring again to FIG. 6A, a sample may be removed from a biopsy deviceby releasing pressurized air into the sample chamber 458 to eject thesample. A device may have a positive displacement pump that generatesthe pressure 406 gradually during an operating cycle, for exampleextending from a time t6 to a time t10 after the sample is taken. Apositive pressure may be generated after the sample is retained in thesample chamber 458, as indicated by the curve 410. In this case, it maybe desirable for a significant initial pressure to exist before thesample chamber 458 is opened 426 to release the sample. The desiredpoint, during the operating cycle 406 of the pump, at which the samplechamber 458 is opened may vary, e.g., 426 or 428, based on thearrangement of the biopsy device and designer preference.

The mechanism of FIGS. 6B to 6E may be employed to provide a delaybetween the operation of the pump and the point at which the samplechamber 458 is opened. For example, if the pump 490 is operated inreverse, and the outer sheath 450 is rotated counter-clockwise, apressure will accrue in the pump 480, while the sample chamber 458remains closed until near the end of the pump cycle. The point at whichthe sample chamber 458 opens can be selected by selecting the initialposition of the outer sheath 450 opening 452 relative to the innersheath 456 opening 454.

Depending on the desired timing, both the pump 480 and the outer sheathmay be moved in a reverse direction during the sample-ejection cycle,which may allow a simpler driving system. For example, if the initialand final positions of the outer sheath 450 are as shown in FIG. 6C, theopening of the sample chamber will occur in the middle of the pumpingcycle in both the sampling and sample-ejection operations. In that case,the entire drive system may simply be reversed to obtain a samplingsequence in which the sample chamber opening is delayed relative to boththe start of the vacuum cycle 402 during sampling and the start of thepressure-generating cycle 406 during sample-ejection. Also, the totalangular displacement need not be 360° as illustrated above.

Referring now to FIGS. 7A to 7B, a sampling sequence may be delayedafter initial operation of a pump without requiring independent drivesystems for the pump and sampling device by another means. A prime mover700 has an output represented by the bar 702 which translates to theright (as shown in the sequence of FIGS. 7A, 7B, and 7C) which indicatesthe displacement of the output 702. This is an illustration of theoutput 702, which could correspond to the shaft of a rotary motor, alinear actuator, a worm drive, or any kind of drive device. A firsttransmission 708 receives motive force from a drive input 704 andapplies an output to a pump 712. A second transmission 710 receivesmotive force from a drive input 706 and applies an output to a samplingdevice 714. As the prime mover output 702 advances it first engages thefirst transmission input 704 as shown in FIG. 7A causing the pump tobegin an operating cycle. As it progresses, the prime mover output 702continues to advance to the point shown in FIG. 7B and as it advances,it continues to remain in engagement with the first transmission input704, but has not yet reached the second transmission input 706.Eventually, the prime mover output 702 advances to the point shown inFIG. 7C and, as it advances, it engages and continues to remain inengagement with the first transmission input 704 and the secondtransmission input 706 to drive both the pump 712 and the samplingdevice 714.

In the foregoing mechanism, it is possible to allow the pump 712 todisengage from the prime mover output 702 at a desired point in thecycle. This may be desirable to level the load on the prime mover 700 sothat it does not require the capacity to operate the pump 712 and thesampling device 714, simultaneously.

Referring now to FIGS. 8A to 8C, another mechanism to provide thesequencing of a pump 712 and sampling device 714, in a similar manner tothat of FIGS. 7A to 7C is to connect the prime mover directly to acombined first transmission input and prime mover output 705. Thiscombined first transmission input applies motive force to the pump 712and, as it translates to the right, continues to operate the pump 712until, as indicated in FIG. 8C, it engages the second transmission input706 and operates the sampling device 714.

Referring now to FIGS. 9A to 9F, a mechanism that conforms to thedescriptions of FIGS. 7A to 7C and 8A to 8C is illustrated. A pump 502,in the form of a syringe, has a piston 508 with a rack 510 whichfunctions as a piston rod, forcing the piston 508. A screw gear 507engages the rack 510 by means of an internal screw (not shown) toadvance the rack 510 to the right. A rotary motor 500 drives a primarydrive gear 506 through an output shaft 501. The primary drive gear 506engages the screw gear 507 to move the rack 510 causing the pump 502 togenerate a vacuum. The vacuum is conveyed by a tube 512, connected to abiopsy needle 524. The vacuum is channeled by the biopsy needle 524 to asample chamber (not shown) near the tip 530 of the biopsy needle 524.The biopsy needle 524 has an outer sheath 526 and an inner sheath 532,which may be as described with reference to any of the embodimentsdescribed above. The outer sheath 526 is able to be rotated relative tothe inner sheath 532 which is affixed to a housing 540 enclosing all ofthe components except distal portion 542 of the biopsy needle 524.

The rack 510 engages a pinion 514 which has a driving bevel gear 516that engages a driven bevel gear 518. The driven bevel gear 518 isaffixed to a sheath driving gear 520 which engages a sheath driven gearaffixed concentrically to the outer sheath 526. The sample chamber isexposed, and a sample is cut, when an opening 528 in the outer sheath526 is rotated by the sheath driven gear 522 at a point in time when therack 510 engages the pinion 514.

During a sampling procedure, the motor is run continuously in a singledirection causing the rack 510 to advance to the right, driven by thescrew gear 507. As the rack 510 moves to the right as illustrated inFIG. 9B, the piston 508 is also advanced, generating a partial vacuum.As the rack 510 moves further it reaches a point where it just engagesthe pinion 516 as shown in FIG. 9C. As the rack moves further still, asshown in FIG. 9D, the pinion is driven along with the rack 510 causingthe vacuum to increase and the outer sheath 526 to begin rotating aboutthe inner sheath 532. The rack continues to advance and, at a pointillustrated in FIG. 9E, the inner sheath opening 527 and the outersheath opening 528 are brought into coincidence thereby opening samplechamber and drawing in a sample due to the suction of the vacuum. Therack advances further (FIG. 9F) causing the sample to be cut placing theouter sheath 526 in a final position. As may be confirmed by inspection,the motor 500 may be operated in reverse to eject a sample by using thepump 502 to generate a pressure and force a tissue sample out of thesample chamber.

The mechanism used to displace the rack 510 can be any suitablemechanism. For example a pinion gear 574 may be used with a drive motor572 which may itself include a gear train, such as a planetary gear, toamplify torque. Another example is a worm gear 576 as illustrated drivenby a suitably arranged motor 570.

Referring now to FIG. 10A, another design for a biopsy device has ahousing 605 that encloses most of the illustrated assembly, as shown. Amotor 600 drives a drive gear 614 which meshes with a screw gear 615which is internally threaded to engage and drive a threaded rod 608. Thethreaded rod 608 is attached to a piston 607 of a pump 602 whichgenerates a vacuum in a tube 606. The tube 606 conveys the vacuum to abiopsy needle 618.

The biopsy needle 618 has an outer sheath 623 and an inner sheath 637.The outer sheath 623 rotates around the inner sheath 637 to bring anopening 620 in the outer sheath 623 into coincidence with an opening 621in the inner sheath 637 and perform a cutting operation as the outersheath. A pin 624 is affixed to the outer sheath 623 which can rotatearound the inner sheath 637.

A pushrod 602 is connected to the threaded rod 608 and is open at thebottom to define a channel 604 so that the pushrod 602 can move withoutinterfering with the tube 606. The pushrod displaces a cam drive 630with a slot 631. The slot 631 has a helical portion 626 and a straightportion 638. A pin 624 is affixed to the outer sheath 623 and engaged inthe slot 631. The cam drive 630 moves to the right as the piston 607 isdisplaced, the cam drive 630 being moved by the piston 607, threaded rod608, pushrod 602, all of which move together. During an initialdisplacement of the piston 607, in which a vacuum is generated, thestraight portion 638 of the slot 631 allows the cam drive 630 to movewithout affecting the position of the pin 624. When the helical portion626 of the slot 631 reaches the pin 624, however, the outer sheath 623is rotated as the piston 607 continues to be displaced. In this way, thecam drive 630 provides for an operation that is similar to that of FIGS.9A to 9F.

FIGS. 11A, 11B and 11C show a stylet 804 that has an axial cuttingsheath 806 which may be used in embodiments of the invention. At the endof the stylet 804, a cutting tip 814 such as a trocar, may be provided.The axial cutting sheath 806 has a cutting edge 808 at a distal endwhich severs tissue samples from the host causing them to be depositedin a tissue basket 802 at the end of the stylet. At the same time, thecutting sheath 806 closes over the tissue basket 802, thereby enclosingit. Note that the relative sizes and proportions of the elements shownin FIGS. 11A and 11B are not essential features of the invention. Notealso that the tissue basket 802 may be a hollow recess configured amanner similar to the embodiments of the figures discussed above. Knownaxially-displacing cutting sheaths rotate about the axis as they aredisplaced. In one embodiment, the cutting sheath is displaced with no,or nearly no, rotational motion. It is believed that for some kinds oftissue sampling, that this results in a higher quality sample, which mayresult from less rubbing of tissue sticking to a rotating cuttingsheath.

FIGS. 12A to 12F show a biopsy needle embodiment for illustratingfeatures including a linear actuator 901, an axial cutting sheath, and aspring-activated cutting action. A linear actuator 901 draws a shaft 903attached to a piston 909 attached to a carriage 907 to generate a vacuumby expanding a volume 940 within a cylinder 905. An interior channel(not shown) of the stylet 931, which runs along its entire length of thestylet 931 from the hose 911 to the sample basket 915, is connected by aflexible hose 911 to the displaced volume 940. As the carriage 907 movesalong the displacement interval between FIGS. 12A and 12B, the displacedvolume 940 expands. This draws air through the hose 911, through theinterior channel of the stylet 931, thereby creating a vacuum in asample basket 915.

A pivot arm 933 is pivotally connected to the carriage 907 about a firstend 939 thereof. A spring 943 generates a torque between a pivot arm 933and a boss 905 on the carriage 907 to keep the free end 935 inengagement with a shelf 937. As the carriage 907 moves, rides along theshelf 937, from the position shown in FIG. 12A, until its free end 935engages a catch plate 925 at the position shown in FIG. 12B. The catchplate 925 is affixed to a cutting sheath 913 which conforms to thedescription attending FIGS. 10A and 10B. A spring 921 connects the catchplate 925 and a boss 923, the boss 923 being fixed relative to thestylet 931. As the carriage 907 moves beyond the position of FIG. 12Btoward the position of FIG. 12C, the cutting sheath 913 is retracted bythe pivot arm 933 stretching the spring 921 thereby increasing arestoring force that urges the cutting sheath back toward a homeposition shown in FIG. 12A. As the cutting sheath 921 is retracted, thesample basket 915 is opened and the vacuum created in the sample basket915 draws host tissue (not shown) into it.

The cutting sheath 921 is further retracted as the carriage 907 movesfurther while the free end 935 slides up a ramp portion 927 of the shelf937 as shown in FIG. 12D. At the same time, the cylinder 905 interiorvolume 940 continues to expand increasing or maintaining the vacuum inthe sample basket 915. At the point shown in FIG. 12E, the free end 935is moved to position in which it disengages from the catch plate 925releasing the cutting sheath 913, thereby permitting the spring 921 toforce it back to the home position of FIG. 12F. The displacement betweenthe positions of FIGS. 12E and 12F causes a tissue sample to be severedby the movement of the cutting sheath 913. The carriage 907 may then bemoved in an opposite direction to cause the free end 935 to return to aposition in which it can retract the cutting sheath 913 again.

In any of the foregoing embodiments, the motors or prime moversdisclosed in each embodiment may be replaced by rotary or linear motorswhich may be driven by electromotive force, by spring motors, hydraulicof pneumatic motors, thermal motors, or by any means of generating amotive force. Different types of displacement (e.g., rotary or linear)can be mapped to the required forms by means of suitable transmissionsaccording to well-known techniques of kinematic design. For example,although the embodiment of FIGS. 12A to 12F shows a linear actuator 901,a drive such as the one shown in FIGS. 9A to 9F or 10A could be used aswell. The linear actuator 901 may be a screw drive, an electronicallycontrolled linear motor, a wax motor, a hydraulic or pneumatic motor, anartificial muscle or any suitable motor with a suitable kinematicmechanism to couple it to the cutting sheath and vacuum pump. Inaddition, although a syringe is preferred as a vacuum generating device,other types of vacuum generating devices may be employed in otherembodiments of the invention, for example, a diaphragm pump,multiple-stroke positive displacement pump, screw pump, etc.

The above-disclosed embodiments may provide at least one of a variety ofadvantages including:

-   -   1. Substantial tissue sample-size can be recovered. For example,        a 14 gauge needle with a suitably-sized sample opening, a 30 to        100 mg. tissue sample, and preferably a 50-60 mg. tissue sample,        may be reliably recovered.    -   2. A single motor may be employed, according to some        embodiments, to provide for vacuum and pressure generation,        tissue sample cutting and recovery, etc.    -   3. The disclosed apparatuses and methods may provide a unitary        disposable device or a unit with a disposable part and a        re-usable part according to different embodiments. For example,        the motor and part of the transmission, the housing and support        elements may be provided in a durable component and the needle,        vacuum generator, and other support elements may be provided in        a disposable part.    -   4. The small number of elements, the power requirements, etc.        are such that the biopsy needle may be provided in a lightweight        and compact form making it easier to handle.    -   5. It is preferable for the biopsy device to have a center of        gravity at its natural hand-hold position. The illustrated        arrangements of elements makes it convenient for the biopsy        device to be arrange for a housing to have a hand-grip that        coincides with the center of gravity.

While the present invention has been disclosed with reference to certainpreferred exemplary embodiments, numerous modifications, alterations,and changes to the described exemplary embodiments are possible withoutdeparting from the sphere and scope of the present invention.Accordingly, it is intended that the present invention not be limited tothe described exemplary embodiments, but that it have the full scope.

1-45. (canceled)
 46. A method of operating a biopsy device in obtainingat least one tissue sample, comprising: inserting a sampling probehaving a first component and a second component into a biological tissuemass, the first component and the second component being rotatablerelative to each other, the first component having a sample chamber anda side port that opens to the sample chamber, and the second componenthaving a side opening; generating a vacuum in the sample chamber duringa first drive interval; rotating at least one of the first component andthe second component of the sampling probe during a second driveinterval until the side port of the first component and the side openingof the second component are in radial alignment; and rotating at leastone of the first component and the second component of the samplingprobe during a third drive interval to sever tissue drawn by vacuum intothe sample chamber to deposit a tissue sample in the sample chamber.47-55. (canceled)
 56. The method of claim 46, wherein the first driveinterval overlaps the second drive interval.
 57. The method of claim 46,wherein the first drive interval overlaps the third drive interval. 58.The method of claim 46, comprising: generating a positive pressure inthe sample chamber during a fourth drive interval; and rotating at leastone of the first component and the second component of the samplingprobe during a fifth drive interval until the side port of the firstcomponent and the side opening of the second component again are inradial alignment to release the positive pressure in the sample chamberto expel the tissue sample from the sample chamber.
 59. The method ofclaim 58, wherein the fourth drive interval overlaps the fifth driveinterval.
 60. The method of claim 58, comprising operating a prime moverto drive a first transmission during the first drive interval to operatea pump to generate the vacuum in the sample chamber.
 61. The method ofclaim 60, wherein the prime mover comprises a motor, and furthercomprising a controller configured to selectively operate the motor inforward and reverse directions.
 62. The method of claim 60, comprisingdriving a second transmission during the second drive interval to rotateat least one of the first component and the second component of thesampling probe until the side port of the first component and the sideopening of the component are in radial alignment.
 63. The method ofclaim 62, wherein the first drive interval overlaps the second driveinterval.
 64. The method of claim 62, comprising driving the secondtransmission during the third drive interval to rotate at least one offirst component and the second component of the sampling probe to severtissue drawn by vacuum into the sample chamber.
 65. The method of claim64, wherein the first drive interval overlaps the third drive interval.66. The method of claim 64, comprising operating the prime mover todrive the first transmission during the fourth drive interval to operatethe pump to generate the positive pressure in the sample chamber. 67.The method of claim 66, comprising driving the second transmissionduring the fifth drive interval to rotate at least one of the firstcomponent and the second component of the sampling probe until the sideport of the first component and the side opening of the second componentagain are in radial alignment to release the positive pressure in thesample chamber to expel the tissue sample from the sample chamber. 68.The method of claim 67, wherein the fourth drive interval overlaps thefifth drive interval.
 69. A method for operating a biopsy device,comprising: providing a biopsy needle having a first cylindrical memberand a second cylindrical member, the first cylindrical member and thesecond cylindrical member being rotatable relative to each other, thefirst cylindrical member having a sample chamber and a side port thatopens to the sample chamber, and the second cylindrical member having aside opening; generating a vacuum in the sample chamber during a firstdrive interval; rotating at least one of the first cylindrical memberand the second cylindrical member of the biopsy needle during a seconddrive interval until the side port of the first cylindrical member andthe side opening of the second cylindrical member are in radialalignment; rotating at least one of the first cylindrical member and thesecond cylindrical member of the biopsy needle during a third driveinterval to sever tissue drawn by vacuum into the sample chamber todeposit a tissue sample in the sample chamber; generating a positivepressure in the sample chamber during a fourth drive interval; androtating at least one of the first cylindrical member and the secondcylindrical member of the biopsy needle during a fifth drive intervaluntil the side port of the first cylindrical member and the side openingof the second cylindrical member again are in radial alignment torelease the positive pressure in the sample chamber to expel the tissuesample from the sample chamber.
 70. The method of claim 69, wherein thefirst drive interval overlaps the second drive interval.
 71. The methodof claim 69, wherein the first drive interval overlaps the third driveinterval.
 72. The method of claim 69, wherein the fourth drive intervaloverlaps the fifth drive interval.
 73. The method of claim 69,comprising operating a pump during the first drive interval to generatethe vacuum in the sample chamber.
 74. The method of claim 73, comprisingoperating the pump during the fourth drive interval to generate thepositive pressure in the sample chamber.